(1) Field of the Invention
This invention relates to a plate fuse and a method of producing the same, and more particularly relates to such a fuse and production method in which a conductive fusible element having a given current capacity is arranged on a surface of an insulation plate.
(2) Statement of the Prior Art
Heretofore, a conventional joint connector has been known from, for example, Japanese Patent Public Disclosure No. HEI 6-333628 (1994). For convenience of explanation, the conventional plate fuse and another type of fuse are described below with reference to FIGS. 26 to 28. FIG. 26 is an explanatory view illustrating a method of producing a conventional plate fuse. FIG. 27 is an explanatory view illustrating a method of producing a conventional plate fuse. FIG. 28 is an exploded perspective view of another conventional fuse.
A plate fuse shown in FIGS. 26 and 27 includes an insulation plate 1 and a fusible element 2 which is formed by etching a metal thin film deposited on the insulation plate 1.
When a current over a given value is applied to the thin film fusible element 2 on the insulation plate 1, the element 2 is heated and melts.
On the other hand, another similar fuse or a blade type fuse, which is not a plate fuse, as shown in FIG. 28, includes a pair of terminals 3, 3 made of a thick metal plate, a string-like fusible element 4 which interconnects the terminals 3, 3 and a resin cover 5.
The conventional plate fuse described above has the following problems.
A current capacity is not accurate, since a part of the heat is absorbed in the insulation plate 1 when the fusible element 2 is heated. Also, the insulation plate 1 produces white smoke or an offensive smell since melting of the fusible element 2 on the insulation plate 1 scorches it.
The conventional plate fuse requires additional working steps and time for etching process or vaporization process.
On the other hand, in the blade type fuse, the terminal 3 requires a thicker metal plate and the string-like fusible element 4 requires to be cut or punched. This results in high production costs. Having a thick metal plate with a large cross sectional area also makes it difficult to form low current capacity and multiple poles.